Conventionally, a filter and a regulator are provided to an air pressure line for supplying compressed air from an air pressure source to a supply destination such as a pneumatic apparatus. The filter is used to eliminate foreign matters contained in the compressed air, such as water droplet, oil droplet, and dust, to purify the compressed air. The regulator is used to regulate the pressure of compressed air to be supplied from the air pressure source to the supply destination, to regulate a set pressure. A filter regulator has a function of eliminating foreign matters contained in compressed air to purify the compressed air and a function of regulating the pressure of compressed air.
The filter regulator includes a port block provided with a primary port and a secondary port. Primary-side compressed air is supplied to the primary port from an air pressure source, and secondary-side compressed air purified and regulated in pressure is discharged from the secondary port. A collection container is removably attached to a lower part of the port block, so that foreign matters contained in compressed air, such as water droplet, is collected and stored in the collection container. The port block is provided with a through-hole, and the primary port and the secondary port communicate with each other via the through-hole. A valve body is provided to a valve shaft provided in the through-hole, and adapted to open and close an opening of the through-hole. A pressure setting mechanism is attached to an upper side of the port block. The pressure setting mechanism is adapted to open and close the valve body on the basis of a secondary-side pressure, thereby regulating the pressure of compressed air to be discharged from the secondary port, to a preset pressure.
A cylindrical filter element is detachably incorporated in the filter. Foreign matters contained in compressed air are eliminated by the filter element which is regularly replaced with new one. Japanese Laid-Open Patent Application Publication No. 2013-150948 describes a gas-liquid separator, i.e., filter that facilitates filter element replacement.